/*
 * Copyright 2002-2018 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package cn.cloud.all.security.core;

import org.springframework.util.Assert;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;

/**
 * A result emitted from an {@link OAuth2TokenValidator} validation attempt
 *
 * @author Josh Cummings
 * @since 5.1
 */
public final class OAuth2TokenValidatorResult {

    static final OAuth2TokenValidatorResult NO_ERRORS = new OAuth2TokenValidatorResult(Collections.emptyList());

    private final Collection<OAuth2Error> errors;

    private OAuth2TokenValidatorResult(Collection<OAuth2Error> errors) {
        Assert.notNull(errors, "errors cannot be null");
        this.errors = new ArrayList<>(errors);
    }

    /**
     * Say whether this result indicates success
     *
     * @return whether this result has errors
     */
    public boolean hasErrors() {
        return !this.errors.isEmpty();
    }

    /**
     * Return error details regarding the validation attempt
     *
     * @return the collection of results in this result, if any; returns an empty list otherwise
     */
    public Collection<OAuth2Error> getErrors() {
        return this.errors;
    }

    /**
     * Construct a successful {@link OAuth2TokenValidatorResult}
     *
     * @return an {@link OAuth2TokenValidatorResult} with no errors
     */
    public static OAuth2TokenValidatorResult success() {
        return NO_ERRORS;
    }

    /**
     * Construct a failure {@link OAuth2TokenValidatorResult} with the provided detail
     *
     * @param errors the list of errors
     * @return an {@link OAuth2TokenValidatorResult} with the errors specified
     */
    public static OAuth2TokenValidatorResult failure(OAuth2Error... errors) {
        return failure(Arrays.asList(errors));
    }

    /**
     * Construct a failure {@link OAuth2TokenValidatorResult} with the provided detail
     *
     * @param errors the list of errors
     * @return an {@link OAuth2TokenValidatorResult} with the errors specified
     */
    public static OAuth2TokenValidatorResult failure(Collection<OAuth2Error> errors) {
        if (errors.isEmpty()) {
            return NO_ERRORS;
        }

        return new OAuth2TokenValidatorResult(errors);
    }
}
